The present invention relates to a device for adjusting the position of a steering wheel of a vehicle and more specifically of an industrial vehicle.
A cabin of an industrial vehicle has to provide a satisfactory driving environment for a vehicle driver but also has to provide a satisfactory living environment. On long haul journeys, the vehicle cabin constitutes the driver's living environment where the driver can rest and eat. It is therefore important that the driver can easily move around the cabin. That is why an industrial vehicle can be equipped with a retractable steering wheel. The steering wheel can be moved in a position substantially above the vehicle dashboard and therefore does not protrude too much into the cabin; thus, once the steering wheel is in a retracted position, the cabin offers more freedom of movement for the driver.
While it is important to offer the driver a comfortable living environment when the driver uses the cabin as a place for resting and relaxing, it is also important that a driver can adjust the position of the seat and the position of the steering wheel according to his/her morphology. To this end, the steering wheel is linked to the vehicle through a mechanism that allows transversal, axial and angular adjustment of the steering wheel position.
Furthermore, to provide easy entry into and exit from the cabin, the steering wheel might be put into a retracted position wherein the steering wheel does not protrude into the cabin. While this function is beneficial for accessing the cabin, it means that the specific position set by a driver is lost when the steering wheel is retracted for easy entry/exit.
By moving the steering wheel into a retracted position, the adjustment of the steering wheel position set by an individual driver is lost. Thus, when the driver moves the steering wheel form a retracted position to a driving position, the driver has to readjust the position of the steering wheel.
Another common problem of the current steering wheel is that when a driver modifies the position of the steering wheel in one direction, the position of the steering wheel is usually altered in other directions. For example when the angular position of the steering wheel is modified, the height of the steering wheel is also modified.
It therefore appears that there is room for improvements in the technical field of steering wheel position adjustment.
It is desirable to provide a device for adjusting the position of a steering wheel which allows comprehensive driving adjustment of the steering wheel position according to the requirements of any individual driver and allows moving the steering wheel into a retracted position while keeping the individual driving adjustment.
According to an aspect of the present invention, a device is provided for adjusting, in a vehicle cabin, the position of a steering wheel secured at the free end of a steering shaft. According to the invention, this device comprises adjusting means for adjusting, in a preferred position, the position of the steering wheel in at least one direction, said adjusting means being supported by retracting means capable of moving the steering wheel into a retracted position wherein the steering wheel does not protrude into the vehicle cabin while maintaining unaltered, with respect to the adjusting means, the preferred position.
Thus, the invention makes provision for a device for adjusting the position of a steering wheel whose kinematic line is divided into a first functional unit—retracting means—that can move with respect to a vehicle body according to, for example, a translation, a rotation or combination of two or more displacement and, operatively connected to the first functional unit, a second functional unit—adjusting means—that allows adjustment of a steering wheel's position according to one or more direction. The device according to the invention makes it possible to maintain the preferred position selected by a driver when the steering wheel is moved into retracted position. The steering wheel preferred position is to be understood as one of the various steering wheel positions that is best suited to a vehicle driver according to the driver's morphology, habit etc.
In a preferred embodiment, the device can comprise a primary bracket jointed onto a vehicle body with at least one degree of freedom; said primary bracket supports the said adjusting means for adjusting the position of the steering wheel in a preferred driving position and is capable of moving according to the at least one degree of freedom into a retracted position wherein the steering wheel does not protrude into the vehicle cabin.
The primary bracket can be rotatably mounted onto the vehicle body as it then allows lifting the steering wheel above a vehicle dashboard which minimizes the steering wheel protrusion into a vehicle cabin.
To permit rotation, the primary bracket can include a pin capable of rotation about one or more bores having a fixed position with regard to the vehicle body.
In a possible embodiment of the invention, the primary bracket can have a U shape comprised of two lateral wings connected by a back plate. U shape has the advantage of providing a sturdy device.
The device can also incorporate locking means capable of immobilizing the retracting means with regard to the vehicle body.
The adjusting means provide comprehensive adjustment of the steering wheel's position. The adjusting means can provide adjustment of the steering wheel position in a longitudinal direction with respect to the primary bracket and/or in a vertical direction with respect to the primary bracket and/or an angular adjustment of the steering wheel with respect to the primary bracket.
In a preferred embodiment of the invention, the device further can comprise a secondary bracket arranged to be movable with respect to the primary bracket along a longitudinal direction and a vertical direction. In functional terms, the secondary bracket provides the basis for adjusting the position of the steering wheel in a preferred position for an individual driver.
The primary bracket can be provided with at least one elongated window along which the secondary bracket is longitudinally guided. It is further envisaged that each lateral wing of the primary bracket is provided with three parallel elongated windows so as to prevent any undesirable play.
The device can further include at least one sliding plate guided by the at least one elongated window onto which the secondary bracket is attached.
To avoid any undesirable play, the device can comprise two sliding plates respectively guided by the elongated windows of each lateral wing of the primary bracket.
In a further preferred feature of the invention, the device can comprise at least two connecting rods having each a first end and a second end, the first end of each connecting rod being rotatably attached to a sliding plate and the second end of each connecting rod being rotatably connected to the secondary bracket, the two connecting rods defining an expanding parallelogram allowing a combined longitudinal and transversal movement of the secondary bracket with respect to the primary bracket.
Each sliding plate can be connected to the secondary bracket with three connecting rods to maintain a steady connection even if from a strictly kinematic view point, two connecting rods are sufficient.
To limit the scope of the secondary bracket movement, the at least one lateral window of the primary bracket can be provided with a polygonal window wherein a pin attached to the secondary bracket is engaged.
To suit most adjustment requirements, the window provided in the lateral wing of the primary bracket can be substantially quadrangular.
In an embodiment of the invention, the secondary bracket has a U shape comprised of two lateral wings connected by a back plate, each lateral wing having connecting pins onto which are connected the second ends of the connecting rods.
An important aspect of the invention is that each joint that forms the kinematic line of the device according to the invention can be locked independently. Therefore each adjustment that is made by a driver can remain unaltered when the steering wheel is moved into a retracted position.
Thus according to various embodiment of the invention, the device can incorporate locking means capable of immobilizing at least one of the sliding plates with regard to the primary bracket and/or the device can incorporate locking means capable of immobilizing the secondary bracket with regard to the primary bracket and/or the device can incorporate locking means capable of immobilizing the secondary bracket with regard to at least of the sliding plate.
According to an advantageous variant of the invention, the device can comprise means for adjustably joining the steering shaft onto the secondary bracket with at least one degree of freedom.
Preferably the device can comprise means for joining the steering shaft onto the secondary bracket capable of angularly adjusting the position of the steering shaft with regard to the secondary bracket.
Thus the steering wheel can be angularly adjusted according to the individual need of a driver. It can be emphasized that the steering wheel angular adjustment is independent from height or longitudinal adjustment. In other words, a driver can adjust the steering wheel's angular position and then adjust the vertical and longitudinal steering wheel position while the steering wheel's angular position remains unaltered.
For the angular adjustment of the steering wheel, at least one lateral wing can be provided with at least one curved opening wherein a steering shaft support is guided along a curved path.
Preferably, each lateral wing of the secondary bracket includes two concentric curved openings wherein two guiding pin are attached onto the two lateral wings of the steering shaft support.
It is envisaged that, the at least one curved opening has a centre of curvature that substantially coincides with the centre of the steering wheel.
Preferably, the device can incorporate locking means capable of immobilizing the steering shaft with regard to the secondary bracket.